The invention herein relates to a playing field surface useful for athletic games such as for tennis courts, football and soccer fields, baseball fields, field hockey playing fields, and the like. Such types of athletic game playing fields have been made of artificial turf or synthetic grass-like carpeting which simulate natural grass fields.
In the past, the artificial turf or simulated grass playing fields generally comprised a grass-like carpeting laid upon a base surface, such as the ground, sand, gravel and the like, appropriately drained and sloped for water drainage purposes. A filling of sand or other particulate or granular material has been applied upon the synthetic grass-like carpeting so that the composite carpet and covering or filler forms the playing surface. Examples of this type of construction are illustrated in my prior art patent, U.S. Pat. No. 4,336,286 issued June 22, 1982 and in the prior patents to Haas, U.S. Pat. No. 3,995,079 issued Nov. 30, 1976 and U.S. Pat. No. 4,044,179 issued Aug. 23, 1977.
In such types of playing field surfaces, it is desirable to have some small predetermined amount of resiliency which, depending upon the particular game, may be desirable for ball bouncing characteristics or for player feel, and the like. The degree and type of resiliency differ in various kinds of games and thus, are difficult to provide in this kind of surface construction. Thus, as illustrated in the above-identified patents, the typical way of providing some degree of resiliency has been to utilize rubber-like carpet bases or resilient underlays, but these are not sufficient for many desired game conditions.
Thus, this invention relates to an improvement in the simulated grass or synthetic turf playing field surfaces wherein a controlled amount of resiliency can be provided as desired.